Share Email Print
cover

Proceedings Paper

Near-contact mode: a novel AFM operation mode for nondestructive ultrahigh lateral-resolution topography measurement in air
Author(s): Huddee J. Ho
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Surface contamination on both the tip and the sample complicates tip-sample interaction when operating an AFM in air. In the traditional non-contact mode using small vibration amplitudes, tip-sample spacing is maintained at a few nanometers, and the tip can be captured by the surface due to the capillary force. A popular method that prevents this tip- capture problem is to vibrate the tip at large amplitude, with the tip contacting the surface periodically. With a combined AFM/SEM system, the tips and samples were found to sustain damage by this periodic-contact. To minimize tip-sample damage and achieve maximal lateral resolution, we studied the surface contamination and the tip-sample interaction in air, and discovered a novel working mode producing one nanometer lateral resolution in air. This method uses a cantilever of large enough force constant to avoid the tip being captured, and small vibration amplitudes of only a few nanometers to avoid tip-sample damage. By combining stiff cantilever and small vibration amplitude, the tip can be maintained in the newly discovered 'near contact' region above the sample surface, so tip-sample spacing is minimized and tip sharpness preserved, achieving ultra-high lateral resolution in air. To explain the working mechanisms, we developed a microscopic model of the tip-sample interaction via the surface contamination layers.

Paper Details

Date Published: 1 September 1998
PDF: 14 pages
Proc. SPIE 3512, Materials and Device Characterization in Micromachining, (1 September 1998); doi: 10.1117/12.324048
Show Author Affiliations
Huddee J. Ho, TopoMetrix Corp. (United States)


Published in SPIE Proceedings Vol. 3512:
Materials and Device Characterization in Micromachining
Craig R. Friedrich; Yuli Vladimirsky, Editor(s)

© SPIE. Terms of Use
Back to Top